[modules] Treat friend declarations that are lexically within a dependent
context as anonymous for merging purposes. They can't be found by their names,
so we merge them based on their position within the surrounding context.

llvm-svn: 228485
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 8862f9f..5f4aa11 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -846,6 +846,10 @@
       return getLexicalParent()->isDependentContext();
   }
 
+  // FIXME: A variable template is a dependent context, but is not a
+  // DeclContext. A context within it (such as a lambda-expression)
+  // should be considered dependent.
+
   return getParent() && getParent()->isDependentContext();
 }